softpipe: setup pixel_offset for all primitive types

softpipe: setup pixel_offset for all primitive types

If we don't update this for all primitive-types, we end up rendering
slightly offset points and lines up until the point where the first
triangle gets drawn. This is obviously not correct, and violates
OpenGL's repeatability rule.

Signed-off-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Fixes: ca9c413647b ("softpipe: Respect gl_rasterization_rules in
       primitive setup.")
Reviewed-By: Gert Wollny <gert.wollny@collabora.com>